RFID (Radio Frequency Identification, radio frequency identification) is a noncontact automatic identification technology, which automatically identifies target objects by radio frequency signals and obtains data without manual intervention. As a wireless version of a bar code, the RFID technology has the advantages of being waterproof, anti-magnetic, high temperature resistant, large reading distance, the data encryption and the like that the bar code does not have. The RFID technology has been gradually applied to all the aspects of industrial production and daily life and has made great strides in such fields as factory production, railway operation, warehousing and logistics, valuable goods trade, and identification at present.
At present, the vast majority of libraries still use bar code systems, the existing bar codes have the following disadvantages: 1. the bar code is a “visual technology”, a scanner must be operated manually and can only receive the bar code within its view field; 2. the data of the bar code cannot be changed; 3 the bar code has higher requirements on the integrity; 4 the bar code can only identify the producer and the product, and cannot identify the specific commodity; and 5 although the bar code only stores a small amount of data, these data are not encoded, an identification code is universal, so the confidentiality and security of the data still have some deficiencies. The radio frequency identification (RFID) technology can solve all of these problems one by one and bring great convenience for the book management in libraries. RSSI signals of the RFID tags are not applied to book sorting in the libraries at present, compared with the book sorting manner of using phase values of the tags, it is more convenient to adopt the RSSI signals.